The present invention relates generally to a process for preparing cation exchange materials from peat, and more particularly to a process for improving the ion exchange capability of peat for removal of toxic and other metal ions from solution and the product produced therefrom.
Ion exchange processes are widely used for removal of certain cations from aqueous solution, including in particular, metal ions which are toxic. Certain ion exchange processes have been utilized to purify water through removal of toxic or otherwise undesirable cations by replacement in solution with less harmful or substantially innocuous ions. In other words, those ions, particularly toxic metal cations, are retained by the exchange material, while releasing generally harmless ions into the treated aqueous solution. The quality of water is accordingly improved through treatment with various ion exchange mediums.
In the past, it has been known to treat peat with sulfuric acid, and thereafter heating the treated peat. Such a process is described in U.S. Pat. No. 2,382,334, wherein certain organic carbonizable raw materials including peat have been treated with a strong sulfonating agent such as concentrated or fuming sulfuric acid. Similar processes are described in U.S. Pat. Nos. 2,191,060 and 2,191,063. While these materials have been useful for a variety of ion exchange applications, the present invention provides an improved ion exchange medium which is capable of higher capacities as well as higher preferences for certain undesirable and/or toxic metallic ions. Stated another way, the process of the present invention modifies the properties of peat so as to produce a peat-based product having improved ion exchange capacities and capabilities.